1. Field of the Invention
The present invention relates to a wireless local access network (WLAN), and more particularly, to a WLAN management procedure and a station supporting the management procedure.
2. Description of the Related Art
With the development of information communication technology, a variety of wireless communication technologies have been introduced. A WLAN is technology permitting wireless access to Internet in specific service areas such as houses, companies, or air planes by the use of portable terminals such as a personal digital assistant (PDA), a laptop computer, and a portable multimedia player (PMP) on the basis of a radio frequency technology.
These days, thanks to the increased availability of WLANs, portable terminal users such as laptop computer users are able to perform their tasks with increased mobility. For example, a user can take his laptop computer from his desk into a conference room to attend a meeting and still have access to his local network to retrieve data and have access to the Internet via one or more modems or gateways present on the local network without being tethered by a wired connection. Similarly, business travelers commonly use their portable terminals to gain access to their email accounts, to check if there is any unread email, and to read and send email.
In the initial WLAN technology, a data rate of 1 to 2 Mbps was supported by the use of frequency hopping, spread spectrum, and infrared communication using a frequency of 2.4 GHz in accordance with the IEEE 802.11. In recent years, with the development of the wireless communication technology, 54 Mbps in maximum can be supported by applying the orthogonal frequency division multiplex (OFDM) technology, etc. to the WLAN. In addition, the IEEE 802.11 has developed or is developing wireless communication technologies for improvement in quality of service (QoS), compatibility of an access point (AP) protocol, security enhancement, radio measurement or radio resource measurement, wireless access in vehicular environment, fast roaming, mesh network, inter-working with external networks, wireless network management, and the like.
The wireless network management procedure for a WLAN provides protocols relevant to the wireless network management, such as allowing a non-AP station or an access point (AP) to collect a variety of information on the wireless network or diagnosing problems of the wireless network. The wireless network management procedure includes an event reporting procedure, a diagnostic reporting procedure, a presence service procedure, a base service set (BSS) transition management procedure, a flexible broadcast multicast service (FBMS) procedure, and a sleep mode procedure. A traffic filter service (TFS) procedure is also included in the wireless network management procedure.
The TFS is a service which an access point (AP) provides to a non-AP station (STA) associated therewith. The AP does not transmit all incoming frames to the associated non-AP STA, but transmits only a frame corresponding to a predetermined condition. In general, since an AP should transmit all frames to a receiving non-AP STA but can transmit only a frame corresponding to a filtering condition in the TFS, it is possible to prevent unnecessary traffics from occurring, thereby enhancing the efficiency in using radio resources. In addition, since a non-AP STA receives and processes only frames necessary therefor, it is possible to reduce the power consumption.